Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Orlistat may decrease how well the levothyroxine works.
What might happen:
You may notice some symptoms of hypothyroidism, which include cold intolerance, feeling tired, dry skin, and constipation.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Separate the times you take your levothyroxine and your orlistat by at least four hours. Let your doctor know if you have any symptoms of hypothyroidism. Your doctor may want to check how your medicine is working with a blood test.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Synthroid (levothyroxine sodium) US prescribing information. Abbott Laboratories June, 2011.
2.Tirosint (levothyroxine sodium) US prescribing information. Institut Biochimique SA (IBSA) December, 2007.
3.Xenical (orlistat) US prescribing information. Roche Laboratories, Inc. August, 2015.
4.Madhava K, Hartley A. Hypothyroidism in thyroid carcinoma follow-up: orlistat may inhibit the absorption of thyroxine. Clin Oncol (R Coll Radiol) 2005 Sep;17(6):492.